Organometallic diphenyl hydrantoins and uses thereof

ABSTRACT

Stable, organometallic complexes of 5,5-diphenyl-2,4 imidazolidenedione (diphenyl hydantoin) are versatile biocides, effective when applied topically or parenterally to animal tissue, and when applied topically to plants. The diphenyl Hydantoin complexes are seen to prevent animal and plant tissue infections, and may be combined with other materials to inhibit infection.

This is a continuation of Ser. No. 07/974,686, filed Nov. 12, 1992, nowU.S. Pat. No. 5,298,624, which, in turn, is a continuation of Ser. No.07/765,460, filed Sep. 25, 1991, (abandoned) which, in turn, is acontinuation of Ser. No. 07/363,288, filed Jun. 2, 1989, (abandoned)which, in turn, is a continuation of Ser. No. 06/862,160, filed May 12,1986, (abandoned) which, in turn, is a continuation of Ser. No.06/570,800, filed Jan. 16, 1984 (abandoned).

BACKGROUND OF THE INVENTION

The compound 5,5-Diphenyl-2, 4 imidazolidinedione, also known asdiphenyl hydantoin, or phenytoin, possesses the structure ##STR1## andhas been used as an anticonvulsant. It is still used in this way,although it has been supplanted, to some degree, by other drugs,especially the hypnotics. See, e.g., F. Buchtal et al., AntilepticDrugs, Raven Press, N.Y., 1972 at page 103. It is more extensively usedas a veterinary anticonvulsant, particularly in the treatment of cats.

Diphenyl hydantoin, its derivatives, and compositions containing theseare known in the art, as may be seen in, e.g. U.S. Pat. Nos. 2,409,754;3,932,449; 3,798,233; 4,091,233; and 4,093,809, the disclosures of whichare incorporated by reference herein. While many uses for hydantoin andits derivatives are disclosed in these references, it is apparent thathydantoin and its derivatives have never been employed as biocides.

Organometallic compounds have been employed in the past as specificbiocides, particularly as antimicrobials. For example, organometallicderivatives of sulfadiazine are among the most prominent of thesematerials. See, e.g. U.S. Pat. Nos. 3,761,590; 4,020,150; 4,049,802;3,792,161; and 4,078,058, in which organometallic compounds ofsulfadiazine are disclosed, such as silver sulfadizine, zincsulfadiazine, and cerium sulfadiazine. The efficacy of these compoundsas antimicrobials is clear from these disclosures, which areincorporated by reference herein.

While each of these complexes exhibits satisfactory effect in particularapplications, no single one of these compounds, or classes of compounds,is effective against a broad range of infections and infective agentssuch as bacteria, viruses, plasmodia, and the like. Additionally,treatment of target infections with the known metallic complexes of,e.g., sulfadiazne, has resulted in the development of mutant strainsagainst which previously satisfactory anti-infection agents are now lesseffective, or noneffective.

Hence it is an object of this invention to provide material useful as aversatile biocide for, but not limited to, bacteria, viruses, plasmodia,and the like.

It is a further object of this invention to provide a process for theproduction of a versatile biocide.

It is a further object of this invention to provide a method oftreatment for treating and/or preventing infection in plant and animaltissue by application of a versatile biocide.

How these and other objects of the invention are accomplished willbecome apparent in the following disclosure.

SUMMARY OF THE INVENTION

The compound 5, 5-Diphenyl-2, 4 imidazolidinedione, i.e., diphenylhydantoin or phenytoin is reacted with compounds containing metallicions under conditions favorable to production of complexes of the formMe(Ph), where Me stands for a metal ion, which may be chosen from, e.g.,Ag, Zn, Cu, Ce, Fe, and Hg and the like, and Ph stands for diphenylhydantoin. The resulting organometallic compounds are useful as biocidesin the treatment of various plant and animal infections, such asbacterial infections, viral infections, fungal infections, parasiteinfections, and infection by insects or other pests.

The resulting organometallic complexes are then applied, eithertopically or parenterally to plant and/or animal tissue so as to preventor to treat an infection. Additionally, the organometallic complexes maybe combined in materials which are designed to prevent infestation orinfection, or to relieve infection.

The fact that low toxicity toward host tissue is observed, particularlyin the case of the argentometallic complex, renders the complex suitablefor use as, e.g., a topical agent in burn therapy or in the treatment ofthe umbilical stump of newborn infants.

Of particular importance is the argometallic compound referred to hereinas silver diphenyl hydantoin. In comparative tests, silver diphenylhydantoin produced results superior to those obtained using silversulfadiazine or sodium sulfadiazine, two compounds of choice in surfacewound and burn therapy.

DETAILED DESCRIPTION OF THE INVENTION

Diphenyl Hydantoin is first converted to its ammonium salt by reactingit with ammonium hydroxide under conditions favoring formation of theammonium salt. Following formation of the ammonium salt, a source of themetal ion with which the diphenyl hydantoin is to be complexed is added.This may be, e.g. Silver Nitrate solution, when the desired product issilver diphenyl hydantoin, but may be any appropriate material whichcontains the metallic ion sought to be complexed. Some of the metallicions which may be so complexed are the ions of Ag, Zn, Cu, Ce, Fe, andHg, among others. The source of metallic ions is added under conditionsfavoring formation of the organmetallic-diphenyl hydantoin complex. Theresulting complexes are, in general, poorly soluble, so the formation ofa precipitate may be taken as a sign that the complex has formed. Silverdiphenyl hydantoin, for example is very insoluble, and precipitates outof the reaction solution almost immediately. Upon precipitation, themetal diphenyl hydantoin is collected, washed free of reactant and ions,and is then dried and readied for use.

The following examples set forth uses of the argentometallic complexsilver diphenyl hydantoin in various situations. The fact that silverdiphenyl hydantoin alone is used should not be taken to limit the scopeof this invention in any way.

The poor solubility of silver diphenyl hydantoin in aqueous media, aswell as its poor diffusibility in agar media, required specialtechniques to achieve usable results. To this end, it was necessary toquantitate action by using a doubling dilution procedure, inMiller-Hinton broth, so as to yield reproducible results.

EXAMPLE I

The effect of silver diphenyl hydantoin at various concentrations uponvarious microorganisms was tested. For each of the microorganisms listedbelow, a culture was grown in Miller-Hinton broth (24 hour culture), andthen diluted at a 1:100 ratio. This diluted culture was then grown foran additional two hours, after which the silver diphenyl hydantoin wasadded. Evaluation of the culture took place 18 hours after the additionof the silver phenytoin. The results are summarized in accompanyingTable 1, which follows on the next page.

                  TABLE I                                                         ______________________________________                                        Effect of Silver Phenytoin on Various Microorganisms                          Minimal Inhibitory Concentration                                              Micrograms of Silver Diphenyl                                                 Hydantoin per Milliliter                                                      Organism       1     10        20  40                                         ______________________________________                                        Enterococcus   -     -         +   ++                                         Group D Strep)                                                                Candida Albicans                                                                             -     -         +   +                                          Klebsiella     +     +         +   ++                                         Seratia        -     +         +   +                                          Pseudomonas    -     -         +   +                                          aeruginosa                                                                    Staphloccoccus -     -         +   +                                          aereus                                                                        ______________________________________                                         + = inhibition.                                                               Organisms grown in MillerHinton broth.                                   

A 24 hour culture was diluted 1:100 and compound was added to a two hourculture of this dilution and evaluated at 18 hours.

Antibacterial action was also demonstrated in pure cultures of organismson blood agar plates.

EXAMPLE 2

Experiments designed to compare the effect of Sodium Sulfadiazine,Silver Sulfadiazine, and Silver Diphenyl hydantoin were performed. Theparameters of the experiments were identical to those set forth inExample 1, and the results are summarized in Table 2.

                                      TABLE 2                                     __________________________________________________________________________    MINIMAL INHIBITORY CONCENTRATIONS                                             Enterococcus Candida A.                                                                          Klebsiella P.                                                                        Seratia M.                                                                           Pseudomonas A.                                                                        Strep A.                             S       SS                                                                              SP S SS                                                                              SP                                                                              S SS                                                                              SP S SS                                                                              SP S  SS                                                                              SP S SS                                                                              SP                               __________________________________________________________________________    Microgram                                                                     of agent                                                                       1    - - -  - - - - - +  - - -  -  - -  - - -                                10    - - -  - - - - - +  - + +  -  + -  - - -                                20    - - +  - - + - + +  ±                                                                            + +  -  + +  - + +                                40    - + ++ - - + - + ++ ±                                                                            + ++ -  + +  + + +                                __________________________________________________________________________     Organisms were grown in MillerHinton broth. A twentyfour hour culture was     diluted 1:100. Compounds were added to two hour cultures and examined for     inhibition at 18 hours. The magnitude of inhibition is estimated and          indicated by +.                                                               S: SODIUM SULPHADIMENE                                                        SS: SILVER SULPHADIAZINE                                                      SP: SILVER DIPHENYL HYDANTOIN                                            

EXAMPLE 3

The efficacy of silver diphenyl hydantoin as a plant fungicide wastested. Silver diphenyl hydantoin and commercial fungicide standardswere ground and suspended in acetone in an amount equal to 6% of theirfinal volume and then suspended in purified water containing 250 ppm ofthe surfactant TREM 014 (polyhydric alcohol esters).

In the preventive tests, which are summarized in Tables 3-6, thesuspensions were sprayed to the point of run-off on the plants, and werethen inoculated 24 hours later with a spore suspension of the fungus asgiven in Tables 3-6. The thus treated plants were then placed in asaturated humidity chamber at 20° C. for 24 hours, and then in a growthroom for an additional 7-12 days. Disease ratings were then made, andrecorded as percent disease control.

Curative tests were conducted in a similar matter, except thatinoculation with spore fungus took place 24 hours prior to applicationof the chemical. The results are summarized in Tables 3-6, which follow.

                  TABLE 3                                                         ______________________________________                                        Evaluation of silver diphenyl hydantoin                                       for the control of grape downy mildew                                         (Plasmopara viticola).sup.1                                                                    Percent Disease Control                                      Compound  Concentration.sup.2                                                                        Preventive.sup.3                                                                         Curative.sup.4                              ______________________________________                                        Silver    100          87         0                                           diphenyl   20          49         0                                           hydantoin  5           24         0                                           Curzate ®                                                                           100          100        100                                                    20           0         100                                                    5            0         0                                           Manzate ®                                                                           100          100        0                                                      20          80         --.sup.5                                               5           40         --                                          ______________________________________                                         .sup.1 Test plants incoculated with an aqueous sporangial suspension (1.0     × 10.sup.5 sporangia/ml).                                               .sup.2 ppm.                                                                   .sup.3 Test plants inoculated 24 hours after application of chemical.         .sup.4 Test plants inoculated 24 hours before application of chemical.        .sup.5 Not tested.                                                            Note:                                                                         Curzate ® is the registered trademark of E.I. du Pont de Nemours & Co     for formulation of 2Cyano-N-(ethyl-amino) carbonyl)2-(methoxyimino)           acetamide                                                                     Manzate ®  is the registered trademark of E.I. du Pont de Nemours &       Co. for formulations of Magnanese ethylenebisdithio carbamate            

                  TABLE 4                                                         ______________________________________                                        Evaluation of silver diphenyl hydontain                                       for the control of tomato late blight                                         (Phytophthora infestans).sup.1                                                                        Percent                                               Compound    Concentration.sup.2                                                                       Disease Control                                       ______________________________________                                        Silver      100         98                                                    diphenyl     20         95                                                    hydantoin    5          17                                                    Curzate ®                                                                             100         100                                                                20         90                                                                 5          40                                                    Manzate ®                                                                             100         100                                                                20         90                                                                 5           0                                                    ______________________________________                                         .sup.1 Test plants inoculated with aqueous sporangial suspension (2.0         × 10.sup.4 sporangia/ml).                                               .sup.2 ppm.                                                              

                  TABLE 5                                                         ______________________________________                                        Evaluation of silver diphenyl hydantoin                                       for the control of apple scab (Venturia                                       inaequalis).sup.1                                                                              Percent Disease Control                                      Compound  Concentration.sup.2                                                                        Preventive.sup.3                                                                         Curative.sup.4                              ______________________________________                                        Silver    100          100        0                                           diphenyl   20          100        0                                           hydantoin  5            60        0                                           Manzate ®                                                                           100          100        0                                                      20           55        0                                                      5            12        0                                           Baycor ®                                                                             20          100        100                                                    5            85        65                                                     1            15        40                                          ______________________________________                                         .sup.1 Test plants inoculated with an aqueous conidial suspension (1.5        × 10.sup.5 condidia/ml).                                                .sup.2 ppm.                                                                   .sup.3 Test plants inoculated 24 hours after application of chemical.         .sup.4 Test plants inoculated 24 hours before application of chemical.        .sup.5 BAYCOR ® is the registered trademark of Bayer AG (Federal          Republic of Germany) and Mobay Chemical Corp., Agricultural Chemicals         Division, for formulations of B (1, 1Biphenyl)-4-yloxy)a (1, 1                dimethylethyl)1H-1, 2, 4 triazoleethanol.                                

                  TABLE 6                                                         ______________________________________                                        Evaluation of silver diphenyl hydantoin                                       for the control of peanut leafspot                                            (Cercospora arachidicola).sup.1                                                                Percent Disease Control                                      Compound  Concentration.sup.2                                                                        Preventive.sup.3                                                                         Curative.sup.4                              ______________________________________                                        Silver    100          78         60                                          diphenytoin                                                                              20          --         0                                           hydantoin  5           16         0                                           Manzate ®                                                                           100          85         0                                                      20          30         0                                                      5            0         0                                           Baycor ®                                                                             20          100        100                                                    5           98         100                                                    1           77         92                                          ______________________________________                                         .sup.1 Test plants inoculated with an aqueous conidial suspension (6.0        × 10.sup.4 condidia/ml).                                                .sup.2 ppm.                                                                   .sup.3 Test plants inoculated 24 hours after application of chemical.         .sup.4 Test plants inoculated 24 hours before application of chemical.   

Organometallic complexes of diphenyl hydantoin, particularly silverdiphenyl hydantoin, are effective against various infectious agents,including bacteria, viruses, fungi, parasites, and insects. It has beenfound, in particular, that silver diphenyl hydantoin is useful againstsilver sensitive parasitic infections, including, but not limited to,all species of malaria-carrying plasmodia sporoza. Thus, silver diphenylhydantoin may be applied in treatement of infections of the blood causedby, e.g., parasites.

Additionally, it is found that diphenyl hydantoin compounds accumulatein tumor cells. Hence, the compound of the invention may be used as wellin the delivery of, e.g., Ag, to tumor cells. The accumulatedorganometallic diphenyl hydantoin complex allows diffusion of the metalion to the tumor cells, resulting in a gradual release of the material.

The method of delivery of the organometallic complex will vary dependingupon the type and extent of the infection being treated or prevented.Topical application may be desirable when the tissue infected exhibits asurface infection such as, e.g., a surface wound or lesion which hasbeen infected. This topical method of application is particularlyappropriate in treating plant tissue infections. Application may beaccomplished parenterally as well, taking the form, e.g., ofsubcutaneous injection, intravenous application, intramuscular injectionand the like. Parenteral application is particularly well suited fortreating animal tissue infections, such as blood or muscle tissueinfections. It is also the preferred method of application when gradualrelease of the organometallic complex is desired, such as in thetreatment of tumor cells.

Some embodiments of the organometallic diphenyl hydantoin complex whichare suited for topical or parenteral application include, e.g., creamsor ointments, wherein one or more inert ingredients are combined withthe complex to aid in its delivery to plant and animal tissue. Liquidcarriers may be used, such as in water dispersions, intravenous fluids,aerosols and sprays. Additional materials which may be used as sourcesfor the organometallic complexes include dusts, dusting powders, andtinctures of the compounds or compositions containing the compounds.

More extensive media may be used as well, for larger scale protectionfrom infection or infestation. While suspensions of organometalliccomplexes may be used to spray plants, e.g., when run-off is not anissue, other media, such as plant stakes treated with the compound, orprotective covers, and the like may be issued. Similarly, the compoundsmay be incorporated with or impregnate dressings such as bandages,mosquito or other protective nets. Mortars, and other building materialsmay also have incorporated or impregnated therein the organometalliccomplexes. These paints, e.g., will then act to render dwellings,shelters, etc. , more infection proof than previously possible.

As will be apparent to those skilled in the art, many modifications,alterations, and substitutions are possible, in light of the foregoingdisclosures, without departing from the spirit of the inventioncontained herein.

What is claimed is:
 1. Silver diphenyl hydantoin ammonium complex.
 2. Amethod of treating a wound or tissue for the prevention or treatment ofan infection and to promote healing which comprises administering silverdiphenyl hydantoin ammonium complex to said wound or tissue.
 3. A methodin accordance with claim 2 wherein said silver diphenyl hydantoinammonium complex is administered topically.
 4. A method in accordancewith claim 2 wherein said infection is a microbial infection.